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Ministry of Agriculture, British Columbia, 1994:

On-farm quick test for estimating Nitrogen in dairy manure, Beltsville Agricultural Research Center, 2000:

United States Department of Agriculture, 2001:

Lietelannan käyttö nurmikierrossa 2002:

Publications not available on the net:

DE: Dr. Hoffmann, Landwirtschaftskammer Weser Ems - Landreport Nr. 28 1983 Seite 5

DK: Kjellerup V. - Kvælstofanalyser af gylle. - Ugeskrift for Jordbrug 1984 nr. 15

DK: Raunkiär S. - N-min bestemmelse efter Agros-metoderne - Effektiv Landbrug 5 marts 1990

FR: Bertrand M. - Methode d´estimation de la valeur fertilisante des lisiers de porcs. - Cemagref 1985

NL: Dr. Ir. L.C.N. de la Lande Cremer - N-meting in mest kan snel, maar ook goed. - Boerderij 22 mei 1985

NO: Lier og Omegn Forsöksring - Årsbok 1990 - Feltmåling av nitrogen i jord.

US: Chescheir, Westerman 1984 - Rapid methods for determining fertilizer value of livestock manures. - ASAE paper no 84-4082

US: Fleming, McLellan, Bradshaw 1993 - On farm measurement of available manure-N. - ASAE Summer meeting

Background P-meter:

DK: Kjellerup V. 1984. - Agros nitrogen meter for estimation ammoniumnitrogen in slurry and liquid manure. Askov forsøgsstation.

FR: Bertrand M. 1985. - Methode déstimation de la valeur fertilisante des lisiers de porcs. - CEMAGREF.(same paper as above)

IE: Tunney H. 1979. - Dry matter, specific gravity and nutrient relationships of cattle and pig slurry. Engineering problems with effluents from livestock. - Ed. Hawkins J.C.

US: Chen Y.R. 1982. - Engineering properties of beef cattle manure. - ASAE paper no 82-4085.

US: Chescheir G.M. et Westerman P.W. 1984. - Rapid methods for determining fertilizer value of livestock manures. - ASAE paper no 84-4082

Arguments to use the Nitrogen meter for manure

The content of Nitrogen in manure varies enormously depending on species of animal, feeding, litter material, water content etc. Slurry from cattle and pigs varies from almoust nought to 8 kg N/m3, while liquid poultry manure contains up to 40 kg N/m3. The cost of artificial fertiliser is ever increasing. It is therefore an advantage to know, rather than guess the beneficial contents of the Nitrogen. To increase your yields and reduce the risk of laid crops it is necessary to know the Nitrogen content at the time of spreading.

EASY TO USE. Measurement is very simple to perform and only takes a few minutes. The manure sample, water and a chemical reagent are added using special measuring vessels. After the lid has been placed in position, the contents are mixed. After a few minutes the result is read off the dial.

ACCURACY. The nitrogen meter is based on a scientifically proved method and works unaffected by solid particles. The divergence from laboratory methods is normally under 5 perc.

Phosphorus Meter. Phosphorus in manure is generally organically bound and follows the DM content. The specific weight of the slurry can be measured with the hydrometer. The Phosphorus content as well as DM can then be read from the table supplied in the kit. A sample of well mixed slurry should be taken preferably in a plastic bucket for this operation. The Phosphorus meter is supplied free of extra charge with the Nova Nitrogen meter.

North Carolina State University - McSafley Jr. - Concepts in agricultural by-product utilization:
"Modern livestock farmers are concerned with optimising the performance of their entire enterprise. This includes utilizing valuable resources such as animal manure. Farmers are becoming very conscious of the value of manure as a source of crop nutrients and as a soil conditioner. However, many farmers have been frustrated in using manure by having to guess at the nutrient concentration. One answer has been to have the manure analysed in a lab. This is a very good practice. However, by the time the results come back from the lab the manure has already been spread. Therefore, such results are only good in telling the farmer the rate of nutrient application already made. Another problem with some analyses is that the units used to describe the results can be confusing. Farmers need a reasonably priced device that can be used to measure manure Nitrogen content on-the-spot. Such a device would allow adjusting application rates as manure Nitrogen concentration varies enormously.

Now a new instrument - the Nitrogenmeter - is available that can accurately determine the plant available Nitrogen - Ammonia and Urea - in manure. This simple device was developed in Sweden by a university researcher. Tests by leading western European universities have confirmed the reliability of the instrument. The device is highly durable and can make an available Nitrogen determination in less than 10 minutes. The results are read in easily understandable units - pounds of available Nitrogen per 1000 gallons. The process uses a much larger sample than do labs. The results obtained from the Nitrogen meter coupled with a complete laboratory analysis for other macro and micro nutrients will help the farmer in managing his valuable resource - manure.

Nitrogen meter for soil

Agros Nitrogen meter for soil is based on a new sampling method, that prevents the influents from soil density and water content. It measures the content of Nitrate-N. The content of Ammonia-N does not vary much. To the soil Nitrogen meter, a new soil auger has been developed".